VALDATION IN JAVASCRIPT
<!DOCTYPE html> <html> </html> <head> <title> Simple HTML webpage with CSS style </title> <script> function validation() { var name=document.form["regform"]["name"]; if(name.value==null||name.value=="") { alert("name cant be blank"); return false; } </script> <!-- Stylesheet of web page --> <style> body { text-align: center; } h1 { color: green; } </style> </head> <body> <h1><form name="regform" onsubmit="return validation()" method="post"> name:<input type="text" name="name"> <input type="submit"> </form></h1> <p>A computer science portal for geeks</p> </body> </html>